Method of exploring ground



June 21, 1932. H. LOwY 1,864,024

us'mon OF EXPLORING GROUND Filed March 9, 1928 2 Sheets-Sheet 1 fie sisJan ce JVaZaraZ Wm lengzk June 21, 1932. -(jwy 1,864,024

METHOD OF EXPLORING enomm Filed March 9. 1928 2 Sheets-Sheet '2Patented" June 21, 1932 mmmrci: rows, or vmmm, anemia unrnon or nxnomaeaouim .a uati n fled March 9, 1928, Serial no. 200,305, and in animalMarch 12, 1921.

"My invention relatesto an. improved method of exploring the ground fordetermining therein the existence, the depth below the ground and withsome restrictions hereinafter more fully referred to also the nature ofstrata below the surface of the ound (flifiering in electric propertiesfrom t e surace. a

I have found that the frequency or the natural wave lengthof electricoscillations produced in an overground high frequency oscillationcircuit depends not onlyu-on the constants of such circuit such as 0 ieresistance, self induction and capacity; but also on the distance ofsuch circuit from bodies more particularly if the latter are conductorsof electricity but that this natural wave length is practicallyindependent of the na-- ture of such bodies. On the other hand it iswell known-that the dampin constant and the oscillation am litude 0 suchcircuit, if within the fiel of action of conductive or nonconductivebodies depends not only on the distance of such circuit from the saidconductive bodies but also on their nature, that is tosay of constantsof the said bodies and more particularly the conductivity anddielectricity constant of the said bodies. I have further found that ifthe natural wave lengths and the damping constants or oscillationamplitudes of an oscillation circuit located in the field of action ofother bodies more particularly conductive ones are plotted as abscis'saeand as ordinates respectively I obtain a practically well defined curvewhich, however varies with the nature of the said body. Thus in Fig. 1 Ihave shown such curves for. a few main classes of bodies; 49 curve 1 isfor oil always accompanied by water,

is for salt water and curve 4 is for ore. these curves diverge withoutintersecting ea c h other fronr one point corresponding to mfinitelygreat-distance. Such curves m1 ht in some cases be determinedtheoretically ut a far more reliable method is to-determine themempirically. Assumlng now land having a dryl noncon- 50 ductive surfacesuch as a desert explored. for'ascertammg whether there are verticalline giving the damping con- 'tions and my graph or table,

curve 2 is for sweet water, curve 3.

astobe' subterranean strata of sweet or salt water, ore or oil I proceedas follows:

I mount'on some points of the land to be lored an oscillation circuitproducing osil ations of a (given natural frequency or wave length an agiven damping constant or oscillation amplitude on some point of theland to be explored. I then determine the natural wave length and daming constant or oscillation amplitude of t e circuit so mounted. I thenmark the values of the wave len h thus found on the abscissa axis andthe amping constant or the oscillation amplitude on the ordinates axis.If then the oint of intersection of the ordinate of the ormer and theabscissa of the latter point falls into or. into close proximity tooneofthe lines of Fig. 1 say the line 2' then this clearly indicatesthat t ere is a layer of sweet water, below the point of observation.

Instead of using a graph, such as shown in the annexed drawing I 'mayobviously also use a table the'horizontal head line givin the variousnatural wave lengths and the le stants' or the oscillation amplitudes ofthe waves produced by the given circuit-but for the present I find agraph more suitable for my purpose; The natural wave length beingpractically a function solely of the distance between the oscillationcircuit and the conductive layer I may number the abscissae by wavelengths and by distances simultaneously.

Thus it will be seen that by my method I' determine by two simple andreliable observanot' only the depth of the layer below the surface ofthe ground but also the nature of such layer.

By repeating these observations at various points 0 the land to beexplored I am able to readily determine the horizontal extent of thelayers and-of their nature.

One of the conditions under which my method is generally applicable isthat the strata or layers are substantially horizontal. 5 If this be notthe case the indications become more or less uncertain. Furthermore-Ican determine by my method-only. the uppermost I conductive layer but,not any layers below the uppermost one, because this latteracts as a 10shield preventing the'reaction of the deeper layers on thecircuits.Therefore my method is in -general not applicable in lands, where thesurface contains moisture to an extent to make it conductive but only inlands havinga dry surface such as deserts.

I prefer to use an oscillation circuit comprislng a substantiallyhorizontal antenna, laid out on the dry ground, but I may also secure myoscillatlon circult to poles or use existing telegraph or telephonelines. Or I may mount m oscillation circuit on air craftswhlchmust 0course fly as nearly as possible in a horizontal plane.

Fig. 2 shows a diagram of an apparatus which in practice has been foundsuitable for the purposes of the invention. The parts 1 to 18 show anelectric oscillation circuit in which oscillations are set up by anelectron valve back-coupling transmitter, parts 19 to 24 indicate theantenna circuit, and is, a metallic partition (Faraday case) between thetransmitter and antenna circuits. In this Figure, 1 and 2' areelectronic valves, 3 and 4 are ammeters for measuring the heatingcurdepth belowthe The numeral 7 indicates the position of the rent, and5' and 6 are adjustable condensers.

. battery for the heating current,8 indicates the position of the anodebattery, and, 9 is the back-coupling coil between the grid and thecathodes The numeral 10 indicates an ad- 'justable condenser in theclosed oscillation circuit, and 11 is a self. induction coil in suchcircuit, 12 being an alternate current an meter; 13, 14, 15, 16 and 17are condensers of constant capacity arranged in parallel to theadjustable condenser. The numeral 18 indicates condensers of constantcapacity be-' tween the grid and the cathode; 19 is the antenna, and '20is a tapped self-induction coil.

-21-is a self induction variometer or a structure of adjustable selfinduction, 22 is a thermo- I the nometer '22 galvanometer preferably ofthe Weston type,

is a coil for coupling the antenna circuit with the closed transmittercircuit, 24 are constant ohmic resistances free from self-induction, and25 are the metallic partitions 1 between the two oscillation circliits.

. The natural wave length set u in the antenna circuit 1924) isdetermlned by adjustable condenser 10 of the circuit untilthethermo-galvaof the antenna circuit shows a transmitter explored as aboveset the aid of the ohmic resistance 24. From this total resistance thusdetermined and from the natural frequency-of the antenna circuit givenby the pointer of the ad'ustable condenser 10 of the transmitter, I finby means of records such as the'graph" shown in Fig. 1- not only the entnature by marking the said found natural wave length and. dampingresistance as abscissae and ordinates, on the said graph, the I curve ofthe said graph into which falls the point having the said abscissa: andordinates determining the nature of'the said layer, its ground beingindicated by the said wave len 2. 'A method etermining the existence,the depth below the ground and the nature of strata, differing inelectricproperties fromthe surface, consisting in determining thenatural Wave length and the damping resistance of an overground highfrequency. oscillation circuit of given constants [at a point of theground to be explored, com aring the'results thus obtained with a grapshowing curves derived from known layers of different nature by markingthe said found natural wave length and damping resistance as abscissaeand ordinates on the said aph, the curve of the said graph into whichalls the point having the said abscissa: and ordinatesv determining thenature of the said layer, its depth below the ground being, indicated bythe said wave length, and repeating thesaid procedui'e atldi erentpoints of the ground to be exp ore In testimony whereof he'afiixed hissignature.

i HEINRICH maximum value of the current passing therethrough in whichcase the two circuits are. in resonance. Then the fr uency in the an-" Ytennacircuitisthesame ast atsetupinthe closed transmitter circuit andindicated by the pointer of the adjustable condenser 10. This frequencyis also the natural frequency of the antenna circuit as afiected by theprescube and nature of the subterranean strata to beexplored.Thenthetotalresistance of the antenna-circuit is determined by the welllmownresistanee substitution method with

